Custom Button added in Ribbon is disabled

Question

I have successfully added a new button in the ribbon. But when I check , it is disabled and I cannot even click it. The following is the code that I have used:

    <?xml version="1.0" encoding="utf-8"?>
        <Elements xmlns="http://schemas.microsoft.com/sharepoint/">
          <CustomAction Id="127690cb-1104-4b69-a3df-8b8c9eba36f9.RibbonCustomAction1"
            RegistrationType="List"
            RegistrationId="115"
            Location="CommandUI.Ribbon"
            Sequence="10001"
            Title="Invoke &apos;RibbonCustomAction1&apos; action">
<CommandUIExtension>
  <!-- 
  Update the UI definitions below with the controls and the command actions
  that you want to enable for the custom action.
  -->
  <CommandUIDefinitions>
    <CommandUIDefinition Location="Ribbon.Library.Actions.Controls._children">
      <Button Id="Ribbon.Library.Actions.RibbonCustomAction1Button"
              Alt="Approve Multiple Forms"
              Sequence="100"
              Command="ApproveMultipleItems"
              LabelText="Approve Multiple Forms"
              TemplateAlias="o1"
              Image32by32="_layouts/15/images/placeholder32x32.png"
              Image16by16="_layouts/15/images/placeholder16x16.png" />
    </CommandUIDefinition>
  </CommandUIDefinitions>
  <CommandUIHandlers>
    <CommandUIHandler
       EnabledScript="javascript:
       function enableMultiApproval()
       {
          context = SP.ClientContext.get_current();
         var web = context.get_web();
         alert('web : ' + web);
         context.load(web);
         var currentlibid = SP.ListOperation.Selection.getSelectedList();
         alert('libraryid : '+    currentlibid);       
         var currentLib = web.get_lists().getById(currentlibid);
         alert('currentLib :' + currentLib);
         var selectedItems = SP.ListOperation.Selection.getSelectedItems(context);
         alert('selectedItems: ' + selectedItems);
       }
       enableMultiApproval();"
     Command="ApproveMultipleItems"
     CommandAction="javascript:alert('test');" />
  </CommandUIHandlers>
</CommandUIExtension >

Please guide.

Answer 1

As pointed by @Robert, Enabled script should return boolean value. Your Enabled script should look like this:

"EnabledScript="javascript:
   function enableBulkApproveButton() {
   var context = SP.ClientContext.get_current();
   return SP.ListOperation.Selection.getSelectedItems(context).length >= 1;
   }
   enableBulkApproveButton();"

I guess you are trying to approve multiple documents in a document library. You can have a look at this code: http://sharepointnadeem.blogspot.in/2011/08/approve-multiple-items-in-document.html

Answer 2

Must not your EnabledScript function return a boolean value; True if the button should be enabled and vice versa.